"I knew my relationship with alcohol was unhealthy when every single time I drank, something that I did not feel okay about happened," Gunsberg said.

"I would hurt someone's feelings or I would say something that, you know, impacted my career, or I would do something or break something or just generally be not a nice human being to be around and I was unable to stop that."

Gunsberg has been sober for eight years. Picture: Supplied/Ten

The TV host added that he was "unable to control" when he drank, and it stopped being a choice.

"I didn't think, 'You know what? I might have a drink.' It was, 'I have to have a drink' - and that wasn't OK," the 43-year-old revealed.

"And for me, once I started, I was unable to stop."

After going through some tough days, Gunsberg quit alcohol for good at the age of 36.

Gunsberg has been open about his struggles with alcoholism in the past, attributing his downward spiral with undiagnosed anxiety and depression.

In 2016, he described his days as the Australian Idol host in the early noughties as a blur due to drinking.

"It was a tornado and it was only once it stopped I stuck my head up and went, 'Did that just happen?," he told the Herald Sun.

"Bear in mind, it was before I got diagnosed, before I was on meds and I was using Australia's favourite and most easily available over-the-counter medicine - alcohol - to take care of what was going on with me."

Years later, amid the breakdown of his first marriage, he hit rock bottom.

He wrote on his blog of the time: "I'm down in the darkness. Idol is over, my marriage is over, I have my divorce beard happening, I'm hiding in my divorce cave - anyone who's been through this will know what I'm talking about. I was in need of a serious reboot and restart."